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2 years ago

How many valence electrons are there in Se atom?

Chemistry

2 answers:

a_sh-v [17]2 years ago

7 0

Answer:

The numer of valence electrons is defined as the number of electrons present in the outer most shell of the atom.So, in the case if selenium, there are 6.

Lena [83]2 years ago

5 0

Answer:

4 valence electrons

Despite the fact that the word silicon has a ubiquitous affiliation with all things electronic, Si itself is not a good electrical conductor. It has 4 valence electrons, meaning that filling its outer shell it can form a very strong lattice with 4 neighboring Si atoms-with no un-bonded electrons remaining

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The pathway by which carbon is transferred from living organisms to the atmosphere is called:

Phoenix [80]

Answer:

cellular respiration

Explanation:

All exergonic processes produced in the cell, through which substances oxidize and chemical energy is released, are grouped under the name of cellular respiration, but to break down an organic molecule the cells employ, mainly dehydrogenations that can be carried carried out in the presence or absence of atmospheric O2 oxygen. There are therefore two types of breathing: aerobic respiration and anaerobic respiration. The latter also called fermentation.

Aerobic respiration (oxidative phosphorylation)

- Use molecular O2.

- It degrades glucose to CO2 and H2O

- Exergonic

- Recovers about 50% of chemical energy

- Present in most organisms.

- It uses enzymes located in the mitochondria.

3 0

3 years ago

Why are metals malleable,ductile,and good conductors

9966 [12]

The energy is transferred throughout the rest of the metal by the moving electrons. Metals are described as
malleable (can be beaten into sheets) and ductile (can be pulled out into wires). This is because of the ability of the atoms to roll over each other into new positions without breaking the metallic bond.

7 0

3 years ago

What is the entropy change of the surroundings

KiRa [710]

Answer: The entropy change of the surroundings will be -17.7 J/K mol.

Explanation: The enthalpy of vapourization for 1 mole of acetone is 31.3 kJ/mol

Amount of Acetone given = 10.8 g

Number of moles is calculated by using the formula:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of acetone = 58 g/mol

Number of moles = $\frac{10.8}{58}=0.1862moles$

If 1 mole of acetone has 32.3 kJ/mol of enthalpy, then

0.1862 moles will have = $\frac{32.3}{1}\times 0.1862=5.828kJ/mol$

To calculate the entropy change for the system, we use the formula:

$\Delta S_{sys}=\frac{\Delta H_{vap}}{T(\text{ in K)}}$

Temperature = 56.2°C = (273 + 56.2)K = 329.2K

Putting values in above equation, we get

$\Delta S_{sys}=\frac{5.828}{329.2}=0.0177kJ/Kmol=17.7J/Kmol$ (Conversion Factor: 1 kJ = 1000J)

At Boiling point, the liquid phase and gaseous phase of acetone are in equilibrium. Hence,

$\Delta S_{system}+\Delta S_{surrounding}=0$

$\Delta S_{surrouding}=-\Delta S_{system}=-17.7J/Kmol$

5 0

3 years ago

This equation shows a ____ refer to this summary equation of photosynthesis to complete the sentences about chemical bonds and r

coldgirl [10]

The balanced chemical equation representing the process of photosynthesis is:

$6 CO_{2} +12H_{2}O-->C_{6}H_{12}O_{6}+6O_{2}$

The reactants in the process of photosynthesis are $CO_{2}$ and H $H_{2}O$ and the products of the reaction are glucose $C_{6}H_{12}O_{6}$ and oxygen $O_{2}$ . Oxygen is the nonpolar covalent gas which is released in the process of photosynthesis. The reactant $CO_{2}$ is a nonpolar covalent gas while the other reactant water $H_{2}O$ has polar covalent O-H bonds.

In the balanced chemical equation, the number of each type of element must be equal on both sides of the reaction.

6 0

3 years ago

What is the reason carbon atoms are the most versatile building blocks of the molecules used by living organisms?

WITCHER [35]

Explanation:

Atomic number of carbon is 6. So, 4 valence electrons are present.

Therefore, it can form 4 covalent bonds with varying bond angles by sharing its valence electrons.

Catenation is also an important property of carbon. Catenation is bonding with atoms of same element. Carbon skeleton can be formed in any direction and can vary in length, branching, and ring structure.

Elements required for making most of the molecules in living organisms are:

C, H, N, O, P and S

Carbon easily form covalents with other 5 elements.

These properties make carbon most versatile building blocks of the molecules used by living organisms.

4 0

3 years ago